Question

From a rifle of mass 4 kg, a bullet of mass 50g is fired with an initial velocity of 35 m/s. callcuate the initial recoil velocity of the rifle

Answer 1

Mass of gun M =4 kg Mass of bullet m= 50g                             =50*10^-3 Initial velocity of bullet, v= 35 m/s Let recoil velocity of the gun be m/s Before firing the bullet both gun and bullet were in rest so total momentum of gun and bullet is zero. After firing Momentum of bullet=mv Momentum of gun=Mv Total momentum of bullet and gun after firing = mv+Mv Since, there is no external force applied on the system.  So, total momentum after firing= total momentum before firing mv+Mv=0 Mv = - mv V = - mv/M      =50*10^-3*35/4      =-0.44 m/s

Answer 2

Hey mate, here is your answer.
m1 =50 g = 0.05 kg (bullet)
m2=4 kg. (rifle)
u1 =0m/s
u2 =0m/s
v1. = 35m/s
v2 = ?
Total momentum before fire = m1u1 + m2u2
= (0.05 × 0) + (4 × 0)
= ( 0) + (0 ) = 0 kg m/s
Total momentum after fire = m1v1 + m2v2
=(0.05 × 35) + (v2)
=(1.75 + v2) kg m/s.

According to law of conservation of momentum:-
Total momentum before collision = Total momentum after collision
0 = (1.75 + v2)
-1.75= v2.
Hope it helps you!!!☺️
Please mark me as Brainliest.